This invention relates to an improved furnace useful for heating a building, and is more particularly concerned with a furnace capable of burning both fluid or solid fuels for the purpose of heating air which is circulated to the rooms of a building.
Many residential dwellings are equipped with fireplaces designed for the burning of wood in the form of logs. In such fireplaces, the fire creates an upward draft causing considerable amounts of air to be taken from the building and transported up the flue or chimney and out of the building. The only heat provided by the burning wood is of a radiative nature, and it generally does not compensate for the amount of heat removed from the building in the form of air exhausted through the chimney. Also, whereas the radiative heat will generally affect only the room in which the fireplace is located, the removal of air from the building will cause other rooms to become colder because of the influx of colder air from outside the building. Most such fireplaces are in effect intended primarily as decor, particularly to many who find the burning of logs to be an aethetically pleasing sight.
For actual heating purposes, most residential homes are equipped with specially designed furnaces wherein a liquid fuel such as gas or oil may be continuously and controllably fed to a burner wherein it heats the walls of a combustion chamber. Heat is transferred from the hot outer walls of the chamber to a circulating stream of air which is conducted to the various rooms of the building.
There are numerous desclosures of improved fireplaces wherein heat generated from the burning of wood or coal is caused to heat walls of a chamber which transfers the heat to a circulating stream of air in a manner similar to that employed with oil and gas operated furnaces. Specific examples of such systems may be found in the following U.S. Pat. Nos. 234,921; 695,840; 1,656,326; 2,154,939; 1,505,407; 2,453,954; 2,791,213; 2,172,356; 2,283,790 and 3,981,292.
Although fireplace structures are known having the capability of burning fluid fuels such as gas in addition to wooden logs, the efficiency of utilization of such fluid fuels is generally poor because the combustion compartment is designed primarily to accommodate logs. Also, there is no provision for the concerted utilization of two different fuels to provide a continuous and controllable amount of heat.
It is accordingly an object of the present invention to provide a furnace capable of efficiently utilizing either solid or fluid fuel. It is another object of the invention to provide a furnace capable of efficiently utilizing either solid or fluid fuel to effect the heating of a stream of air which may be circulated to rooms of a building other than the one containing said furnace. It is a still further object of the present invention to provide a fireplace furnace capable of utilizing either a solid or fluid fuel in a manner to provide a continuous and controllable amount of heat. These objects and other objects and advantages of the invention will be apparent from the following description.